Harnessing the potential of oxygenases in plant specialized metabolism

Plant-specialized metabolism accounts for an unparalleled source of the chemical pool that executes diverse and unexpected plant functions. The oxidative enzymes, iron-bound heme-dependent monooxygenases and non-heme iron-dependent oxygenases are the major players in generating the chemical diversity in plants. The reactions catalyzed by oxygenases act as crucial synthetic workhorses in plant metabolism (both primary and specialized), herbicide metabolism, cellular regulation and ecological fitness. As many plant specialized metabolites (PSMs) are utilized as drugs and commodity chemicals, plant oxygenases are the ideal target and represent a promising toolset. Recent advancements in omics-based, analytical and computational biology approaches have enabled plant biologists to expand the pathway diversity through the identification and biochemical characterization of novel oxygenase enzymes. Furthermore, metabolic engineering and synthetic biology approaches have opened new avenues for the sustainable production of plant natural products. This review describes various families of plant oxygenases, their reaction mechanisms, and their involvement in the biosynthesis of PSMs. Additionally, it offers a detailed overview of methodologies used to engineer oxygenases for increasing product titer.